Forming tissue paper by pressing the web while on an uprunning forming wire and transferring the web directly to a yankee dryer

ABSTRACT

1. IN A MACHINE FOR MAKING FIBROUS WEBS SUCH AS TISSUE AND THE LIKE, AN ENDLESS TRAVELING PLASTIC FORMING WIRE HAVING AN UPRUNNING FORMING RUN HAVING AN INCOMING END AND A LONGITUDINALLY SPACED OUTGOING END, A YANKEE DRYER INCLUDING A HEATED DRUM AT THE OUTERGOING END OF TETHE FORMING RUN OF THE WIRE AND HAVING A POLISHED PERIPHERAL SURFACE, A STOCK INLET ADJACENT THE INCOMING END OF THE FORMING RUN OF THE WIRE LAYING STOCK IN THE FORM OF TANGLED FIBERS IN AQUEOUS SUSPENSION ON THE TOP SURFACE OF THE FORMING RUN OF THE WIRE AT SUBSTANTIALLY THE SPEED OF TRAVEL OF THE FORMING RUN, MEANS DOWNSTREAM OF SAID STOCK INLET REMOVING WATER FROM THE WEB AND A SAVE-ALL FOR CATCHING THE WATER PRESSURED FROM THE WEB AND FALLING THROUGH THE WIRE SAID WATER REMOVING MEANS INCLUDING GROOVED PRESS ROLLS ON OPPOSING SIDES OF THE WIRE FOR PRESSING WATER FROM THE WEB ON THE WIRE, A SUCTION COUCH ROLL DEFINING THE OUTGOING END OF THE FORMING RUN OF THE WIRE, AND REMOVING SUFFICIENT MOISTURE FROM THE WIRE TO PASTE THE WEB TO SAID HEATED DRUM, A CONTACT ROLL TRAINING THE WIRE FROM SAID COUCH ROLL TANGENTIALLY OF SAID HEATED DRUM AND COOPERATING WITH SAID COUCH ROLL TO LAY THE NEWLY FORMED WEB ON THE HEATED DRUM, A DOCTOR SPACED ABOUT SAID JEATED DRUM AT LEAST 270* FROM THE POINT OF TANGENCY OF THE WIRE TO SAID HEATED DRUM AND TRANSFERRING THE FORMED WEB FOR COILING.

Nov. 5, 974 D. A. ELY ETAL 3,846,228

FORMING TISSUE PAPER BY PRESSING THE WEB WHILE ON AN UPRUNNING FORMING WIRE AND TRANSFERRING THE WEB DIRECTLY TO A YANKEE DRYER Filed Nov. 13, 1972 United States Patent @ffice 3,846,228 Patented Nov. 5, 1974 3,846,228 FORMING TISSUE PAPER BY PRESSING THE WEB WHILE ON AN UPRUNNING FORMING WIRE AND 'IRANSFERRING THE WEB DIRECTLY TO A YANKEE DRYER Donald A. Ely, Roscoe, 11]., and Thomas G. McKie, Beloit, Wis., assignors to Beloit Corporation, Beloit,

Wis.

Filed Nov. 13, 1972, Ser. No. 306,020 Int. Cl. D211? ]/00, 2/00, 9/02 US. Cl. 162-406 6 Claims ABSTRACT OF THE DISCLOSURE A lightweight or tissue paper forming system wherein the slurry is discharged onto the uprunning portion of a forming wire and after dewatering by the use of pposed press rolls is transferred directly to the heated surface of a Yankee dryer drum. The transfer is accomplished by wrapping the forming wire around a suction couch roll and training the wire away from the couch roll tangentially of the dryer drum. A felt or imprinting fabric may contact the formed web while on the dryer ldrum surface prior to being creped therefrom by a doctor lade.

The Field of the Invention Paper making machine and process for making tissue paper in which a Yankee dryer takes the place of the conventional pressing and multiple drying stages.

Summary, Advantages and Objects of Invention Paping making machine of the Yankee dryer type, in which the web does not favorably respond to most types of presses and rough handling and is dewatered while on the forming wire, and transferred from the forming wire in its dewatered state directly to the drum of a Yankee dryer, and is creped or doctored from the surface of the dryer, for coiling or other operations thereon.

An advantage of the present invention is the provision of a paper making machine for forming comparatively delicate lightweight paper webs or other non-woven fabrics, in which the usual handling of the paper from the Fourdrinier wire to the Yankee dryer is minimized by transferring the web from the forming Wire directly to the drum of the Yankee dryer.

A principal object of the present invention, therefore, is to provide a machine and process for making lightweight non-woven web, constructed with a view towards forming the web with a minimum of rough handling of the web.

Still another object and advantage of the present invention is to simplify the making of non-fibrous webs and particularly lightweight tissues, by laying a high speed jet-stream of fibers in an aqueous solution on the uprunning run of a Fourdrinier wire, removing a large part of the water from the web while forming and traveling along the forming wire, and then continuing the dewatering and drying by transferring the web directly from the forming wire to the heated drum of a Yankee dryer.

Another object of the invention is to provide an improved paper making machine and process arranged with a view toward eliminating the intermediate steps between the forming wire and Yankee dryer, for making tissue sheet in a more efiicient and simplified manner than formerly.

Other objects, features and advantages of the invention will be readily apparent from the following description of a preferred embodiment thereof, taken in conjunction with the accompany drawing, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure.

Description of the Drawing FIG. 1 of the drawing diagrammatically illustrates an apparatus for forming fibrous webs in accordance with the principles of the present invention; and

FIG. 2 is a fragmentary diagrammatic view illustrating a modified means for dewatering the pulp while on the wire.

Description of Preferred Embodiment of Invention In the embodiment of the invention diagrammatically illustrated in the drawing, we have illustratively shown a looped Fourdrinier or forming wire 10 having a forming run 11 defined by a breast roll 12 at the incoming end of the forming run and a couch roll 13 at the outgoing end of the forming run. The wire 10 is preferably a plastic wire made from an endless plastic mesh which may be of 60 mesh or greater and may be made from polyamide fibers, vinyl fibers or polyester fibers sold under the trade names of nylon, Saran, Orlon and Dacron, respectively. The forming run 11 is herein shown as being upwardly inclined, but need not necessarily be so inclined and may extend in any suitable direction.

Spaced along the wire on the outgoing side of the breast roll 12 and disposed over a save-all 15 is a conventional stock inlet 16 shown in a diagrammatic form as being supplied with pulp from a conventional stock feed means through a pump 17. The stock inlet 16 may deliver a substantially uniform high speed jet-stream of pulp in the form of tangled fibers in aqueous suspension and lay the pulp on the wire through an inlet slice 19, diagrammatically shown as being disposed over the save-all 15 on the uprunning side of the breast roll 12. The forming wire 10 is adapted to be driven at substantially the relatively high speed jet-stream of the stock, as it is laid onto the wire from the inlet slice 19. The drive to said forming wire may be of a conventional form so need not be shown or described herein.

The save-all 15 is diagrammaticaly shown as being relatively large and positioned just beneath the forming run 11 of the wire and the inlet slice 19 adjacent the incoming end of the forming run 11 to collect a greater part of the water flowing freely from the stock suspension through the forming run 11 of the wire.

It will here be appreciated that in the case of comparatively lightweight fibrous web formations there is a substantial amount of water to be handled, and this water will flow quite readily through the forming run of the wire during web formation (not only at the time of initial web formation in the upstream region of the immediate discharge of stock from the inlet slice 19, but also farther upwardly along the upwardly inclined forming run 11). This is particularly the case with tissue where the lightweight web offers less resistance to the free flow of water through the web and through the forming run 11 to the save-all 15.

Although the relatively lightweight web forming on the forming run 11 offers nominal resistance to the flow of water therethrough and into the save-all 15, it will be appreciated that the weave of the forming run of the wire 11 plus the depositing of fibers in aqueous solution thereon will afford a certain amount of resistance to the water flow through the wire 11 and into the save-all 15, to the end that there will tend to be a pool of aqueous suspension traveling along the top of the forming run 11 of the Wire, which will drain from the web and wire during travel of the wire along the save-all.

Cooperating press rolls 18, 18' are shown as being spaced down-stream of the inlet slice 19. The lower press roll 18 is disposed within the save-all 15 and the two press rolls serve to press and dewater the Web as it travels along its forming run. The press rolls 18 and 18a are shown as being grooved rolls such as are shown in the United States Pat- 3 cuts to E. J. Justus Nos. 3,198,693; 3,198,694; 3,198,695; 3,198,696 and 3,198,697 to accommodate the free flow of air between the rolls and the wire as the wire passes to the couch rolls 13.

In FIG. 2 of the drawing, a foil or wiper 21 of a conventional form is shown as an alternate means for removing water from the wire. The foil 21 is diagrammatically shown as being within the save-all and in position to wipe the underside of the forming run 11 of the wire to facilitate dewatering of the web and wiping droplets or bodies of water that may be inclined to adhere to the underside of the forming run 11. The foil may be of a type like that shown and described in the United States Patent to A. C. Roecker 3,377,236, dated Apr. 9, 1968 so not herein shown or described in detail. The foil may also be a conventional type of suction foil in which suction aids in the wiping of water from the wire in a manner well-known to those skilled in the art, so not herein shown or described in detail.

While we have herein shown only one foil 21, it will be appreciated that more than one foil may be provided if desired or required for certain types of webs.

A contact roll 22 trains the wire from the couch roll 13 tangentially of the polished surface of a heated drum 23 of a Yankee dryer 24. A second contact roll trains the wire back to the breast roll 12. The contact rolls 22 and 25 may be adjustable to adjust the line of travel of the wire as it leaves the couch roll 13 and to adjust the tension of the wire, it of course being understood that the wire is driven at a uniform linear speed approaching or faster than the speed of discharge of the stock from the inlet slice 19.

The couch roll 13 is shown as a conventional form of suction roll for further dewatering the web to a consistency where it will be pasted to the face of the drum 23 and be carried thereby under a hood 26 extending partially about said drum.

A grooved roll, like the grooved rolls 18 and 18' may be used in place of a suction roll in certain cases, to accommodate the free flow of air between the roll 13 and the Wire 11, as the wire passes to the contact roll 22 and the web is pasted on the drum 23.

The couch roll 13 may be adjustably moved toward and from the heated drum 23 as indicated by the doubleheaded arrow 27, to press a newly formed web or sheet to the face of the heated roll 23 under a preselected pressure.

Where it is desired to imprint a pattern on the web to add bulk to the web the couch roll pressing the web against the surface of the dryer drum 23 may serve to imprint the pattern of the wire 10 on the web.

The hood 26 extends partially about the heated drum 23 to contain the heat of the drum to the sheet and may also serve as a plenum or encase a series of plenum chambers (not shown) directing heated air to the surface of the web as required, and removing moist air from the web to attain a dried product as the sheet or web W is creped or doctored from the surface of the heated drum 23 by a doctor 29.

The doctor 29 may be a conventional form of doctor, doctoring the sheet from the drum 23 and may be followed by a second doctor 30 doctoring broke from the surface of the drum 23 and maintaining the surface of the drum 23 clean. Any broke doctored from the surface of said drum in collected in a broke chute 31.

We.have also shown a pressure roll 32 pressing a felt 33 against the web on the drum 23. The felt 33 is trained in an endless path about direction changing idlers 34 and under a tension roller 35, which is shown as being adjustable. The felt on its return path may also pass between a pair of wringer rolls 36 expressing water from the felt to be collected in a save-all 37. The pressure roll 32 may be suitably driven at the linear speed of the web, by power in a manner well-known to those skilled in the art. Said pressure roll may be of any conventional form, mounted for adjustable movement towards and from the surface of the drum 23 in a suitable manner, so need not herein be shown or described further. The wringer rolls 36 may also be conventional forms of wringer rolls used to wring water from felt.

Where it may be required or desired to imprint a pattern on the web W, and may not be feasible to do this by the plastic wire 10, the felt 33 may be an imprinting fabric in the form of a mesh and made from a plastic material of fibers sold under the trade names of nylon, Saran, Orlon or Dacron.

In the drawing, the doctor 29 is shown as positioned about the drum 23 more than 270 from the point of tangency of the wire 10 to said drum. The dried sheet or web W as creped or squeegeed from the drum 23 by the doctor 29 may pass under a contact roll 39, between a pair of tension rolls 40, maintaining tension on the sheet as it leaves the drum 23, under a second contact roll 41 about a roll 42 and coiled or wound on a winder roll 43 into a coil 44. The coiling of the formed tissue is no part of the present invention so need not herein be shown or described further.

We claim as our invention:

1. In a machine for making fibrous webs such as tissue and the like,

an endless traveling plastic forming wire having an uprunning forming run having an incoming end and a longitudinally spaced outgoing end,

a Yankee dryer including a heated drum at the outgoing end of the forming run of the wire and having a polished peripheral surface,

a stock inlet adjacent the incoming end of the forming run of the wire laying stock in the form of tangled fibers in aqueous suspension on the top surface of the forming run of the wire at substantially the speed of travel of the forming run,

means downstream of said stock inlet removing water from the web and a save-all for catching the water pressed from the web and falling through the wire,

said water removing means including grooved press rolls on opposing sides of the wire for pressing water from the web on the wire,

a suction couch roll defining the outgoing end of the forming run of the wire, and removing sufiicient moisture from the wire to paste the web to said heated drum,

a contact roll training the wire from said couch roll tangentially of said heated drum and cooperating with said couch roll to lay the newly formed web on the heated drum,

a doctor spaced about said heated drurn at least 270 from the point of tangency of the wire to said heated drum and transferring the formed web for coiling.

2. The machine of claim 1, wherein the wire is pressed to the heated drum by said couch roll and imprints a pattern on the web in passing to said drum to increase the bulk of the tissue as delivered to said drum.

3. The machine of claim 1,

wherein the plastic forming Wire is of at least 60 mesh, and the forming run thereof serves to drain water from the web as passing to said couch roll, and

wherein the couch roll draws water from the web to an extent sufficient to adhere the web to said drum as pressed into engagement therewith by said couch roll.

4. The machine of claim 1,

wherein the means removing water from the wire includes a wiper foil engaging the underside of the wire along the forming run thereof disposed above the means catching the water falling through the Wire.

5. A process for the manufacture of tissue and the like,

which comprises the steps of:

delivering a substantially uniform high speed jet-stream of pulp in the form of tangled fibers in aqueous suspension along an uprunning forming run of a forming wire to form a web thereon,

pressing water from the web and wire in the forming run,

passing the wire and formed web about a suction couch roll and further removing water from the web while passing about the couch roll to maintain the moisture content of the web sufficient to adhere to the traveling surface of the heated drum of a Yankee dryer,

pasting the upper side of the web to the heated drum of the Yankee dryer as the wire and web are passing about the couch roll with the wire side of the web facing outwardly,

applying pressure to the web with the outgoing side of the wire while pasting the web onto the heated drum of the Yankee dryer by removing the wire tangentially from the heated drum,

pressing a water receiving felt against the web on the dryer at a press location a distance after the web is pasted on the drum and pressing water from the web into the felt,

said felt being the sole member pressed against the web at said press location,

passing the web about the heated drum of the Yankee dryer for a greater portion of the circumference thereof,

then removing the formed web from the heated drum of the Yankee dryer for coiling.

6. In a machine for making fibrous webs, such as tissue and the like,

an endless traveling plastic forming wire having an uprunning forming run having an incoming end and a longitudinally spaced outgoing end,

a Yankee dryer including a heated drum at the outgoing end of the forming run of the wire and having a polished peripheral surface,

a stock inlet adjacent the incoming end of the forming run of the wire laying stock in the form of tangled fibers in aqueous suspension on the top surface of the forming run of the wire at substantially the speed of travel of the forming run,

means downstream of said stock inlet pressing water from the web and a save-all for catching the water pressed from the web and falling through the wire,

a suction couch roll defining the outgoing end of the forming run of the wire, and removing sufiicient moisture from the wire to paste the web to said heated drum,

a contact roll training the wire from said couch roll tangentially of said heated drum and cooperating with said couch roll to lay the newly formed web on the heated drum,

a press roll forming a press nip with the drum positioned a distance around the drum after the location of the couch roll,

and a water receiving felt passing through a nip between the press roll and drum receiving water from the web on the drum,

said felt being the sole member passing through the nip with the web,

means dewatering said felt,

a doctor spaced about said heated drum at least 270 from the point of tangency of the wire to said heated drum and transferring the formed web for coiling.

References Cited UNITED STATES PATENTS 3,745,066 7/1973 Bleuer 162-203 X 3,301,746 1/1967 Sanford et al. 162-206 X 3,224,928 12/1965 Lee et al. 162-203 X 3,377,236 4/1968 Roecker 162-352 X 2,225,435 12/1940 Kellett et al. 162-352 X 3,537,954 11/1970 Justus 162-113 X 3,150,037 9/1964 Lee 162-348 X 3,198,695 8/1965 Justus 162-359 3,266,976 8/1966 Brezinski 162-358 X S. LEON BASHORE, Primary Examiner R. H. TUSHIN, Assistant Examiner US. Cl. X.R. 

1. IN A MACHINE FOR MAKING FIBROUS WEBS SUCH AS TISSUE AND THE LIKE, AN ENDLESS TRAVELING PLASTIC FORMING WIRE HAVING AN UPRUNNING FORMING RUN HAVING AN INCOMING END AND A LONGITUDINALLY SPACED OUTGOING END, A YANKEE DRYER INCLUDING A HEATED DRUM AT THE OUTERGOING END OF TETHE FORMING RUN OF THE WIRE AND HAVING A POLISHED PERIPHERAL SURFACE, A STOCK INLET ADJACENT THE INCOMING END OF THE FORMING RUN OF THE WIRE LAYING STOCK IN THE FORM OF TANGLED FIBERS IN AQUEOUS SUSPENSION ON THE TOP SURFACE OF THE FORMING RUN OF THE WIRE AT SUBSTANTIALLY THE SPEED OF TRAVEL OF THE FORMING RUN, MEANS DOWNSTREAM OF SAID STOCK INLET REMOVING WATER FROM THE WEB AND A SAVE-ALL FOR CATCHING THE WATER PRESSURED FROM THE WEB AND FALLING THROUGH THE WIRE SAID WATER REMOVING MEANS INCLUDING GROOVED PRESS ROLLS ON OPPOSING SIDES OF THE WIRE FOR PRESSING WATER FROM THE WEB ON THE WIRE, A SUCTION COUCH ROLL DEFINING THE OUTGOING END OF THE FORMING RUN OF THE WIRE, AND REMOVING SUFFICIENT MOISTURE FROM THE WIRE TO PASTE THE WEB TO SAID HEATED DRUM, A CONTACT ROLL TRAINING THE WIRE FROM SAID COUCH ROLL TANGENTIALLY OF SAID HEATED DRUM AND COOPERATING WITH SAID COUCH ROLL TO LAY THE NEWLY FORMED WEB ON THE HEATED DRUM, A DOCTOR SPACED ABOUT SAID JEATED DRUM AT LEAST 270* FROM THE POINT OF TANGENCY OF THE WIRE TO SAID HEATED DRUM AND TRANSFERRING THE FORMED WEB FOR COILING. 